Impact of Different Fracture Fluid and Stress Shadow on Productivity of the Multi-Stage Fractured Marcellus Shale Horizontal Wells

Abstract

This study investigates the effect of fluid type and stress shadow on proppant transport and the productivity of a multi-stage fractured Marcellus Shale horizontal well. Additionally, the relation between stress shadow and effective stress is studies to optimize fracture effectiveness. This study’s findings can be compared with similar study performed on a different Marcellus shale well. Furthermore, the extent to which various fracture properties contribute to production is evaluated. The available core plugs measurements, well logs, and the image logs were analyzed to determine the shale petrophysical and geomechanical properties including natural fracture (fissure) distribution to develop a model for Bogges-5H well. The available laboratory measurements and published data were analyzed to determine the gas adsorption characteristics and the shale compressibility. The impact of the shale compressibility was then incorporated in the model by developing multipliers for different compressibility components, i.e., fissure, matrix, and hydraulic fracture as function of net stress. A hydraulic fracture model was then coupled with the reservoir model. The combined model was employed to investigate the impact of fluid type, stress shadow, and stage spacing on proppant transport and the gas production. The model’s credibility was confirmed by a close match between the actual and predicted production. The fracture heights induced by all the fluids remained within the pay zone and the entire fracture height contributed to the production. The High Viscosity Friction Reducer (HVFR) resulted in relatively larger fracture volume (increased fracture height) as compared to the Slickwater leading to improved productivity. The crosslinked gels also improved the productivity but were found to be inferior to HVFR. Stress shadow was found to influence the proppant transport and to impact the hydraulic fracture properties and gas production adversely. The adverse impact of the stress shadow on the production is more pronounced during early production due to higher production rates. The findings in this study can be used for fracture treatment design in the Marcellus shale by optimum fluid selection and the stage spacing to reduce the impact of the stress shadow.